gnu: Move content of openssl module into tls module.

* gnu/packages/openssl.scm (openssl, perl-net-ssleay): Move to...
* gnu/packages/tls.scm: ...here.
* gnu/packages/openssl.scm: Delete file.
* gnu-system.am (GNU_SYSTEM_MODULES): Unregister deleted file.
* gnu/packages/{admin.scm, bittorrent.scm, certs.scm, ci.scm,
  cyrus-sasl.scm, databases.scm, dns.scm, ebook.scm, enlightenment.scm,
  gnunet.scm, libreoffice.scm, links.scm, mail.scm, messaging.scm,
  networking.scm, ntp.scm, openldap.scm, package-management.scm, pdf.scm,
  python.scm, qt.scm, rdesktop.scm, rdf.scm, ruby.scm, ssh.scm,
  synergy.scm, tor.scm, version-control.scm, video.scm, vpn.scm,
  w3m.scm, web.scm, weechat.scm, xiph.scm}: Adapt module import.

Merge branch 'master' into core-updates

Merge branch 'master' into gtk-rebuild

Conflicts:
	gnu/packages/gtk.scm

gnu: zathura: Update to 0.3.3.

* gnu/packages/pdf.scm (zathura): Update to 0.3.3.

Merge branch 'master' into core-updates.

Merge branch 'wip-glib' into master.

Conflicts:
	gnu/packages/package-management.scm

gnu: poppler: Update to 0.32.0.

* gnu/packages/pdf.scm (poppler): Update to 0.32.0.

Merge branch 'master' into core-updates

gnu: xpdf: Fix detection of freetype.

* gnu/packages/pdf.scm (xpdf)[configure-flags]: Add flag to correctly detect
  freetype. Otherwise, the xpdf binary is not built.

gnu: podofo: Fix detection of freetype.

* gnu/packages/pdf.scm (podofo)[arguments]: Add phase patching the cmake
  file that looks for freetype.

gnu: Add zathura comicbook plugin.

* gnu/packages/pdf.scm (zathura-cb): New variable.

gnu: Add zathura postscript plugin.

* gnu/packages/pdf.scm (zathura-ps): New variable.

gnu: Add zathura DjVu plugin.

* gnu/packages/pdf.scm (zathura-djvu): New variable.

gnu: Add zathura PDF plugin.

* gnu/packages/pdf.scm (zathura-pdf-poppler): New variable.

gnu: Add zathura.

* gnu/packages/pdf.scm (zathura): New variable.
* gnu/packages/patches/zathura-plugindir-environment-variable.patch: New file.
* gnu-system.am: Add it.

Merge branch 'master' into core-updates

gnu: Add Xournal.

* gnu/packages/pdf.scm (xournal): New variable.

gnu: podofo: Add optional input lua.

* gnu/packages/pdf.scm (podofo): Add optional input lua-5.1.

gnu: podofo: Update to 0.9.3.

* gnu/packages/pdf.scm (podofo): Update to 0.9.3.

gnu: podofo: Enable building a shared library.

* gnu/packages/pdf.scm (podofo): Enable building a shared library in addition
    to a static one.